He said: “Our party has always been a broad church, and despite my principled differences with Jeremy over many issues of defence, foreign policy and national security, I agreed to serve on his front bench because of the mandate he was given, his assurances that honesty and difference were welcomed, and due to the many areas we agreed wholeheartedly on such as fighting the vicious Tory trade union bill – which I was proud to lead our work on – cuts to tax credits and tackling climate change.

“I was therefore dismayed that two of our most able and experienced colleagues have been sacked for speaking out in the straight talking and honest way that I believe the public expect and want from their representatives - let alone when it comes to matters of national security.

“I agree entirely with the words Pat McFadden used in denouncing terrorism and the false narrative that the West is to blame, and so I believe the only honourable thing for me to do, when a fellow team member has been singled out for punishment for speaking with honesty and principle on this critical issue, is to leave the front bench.

“Jeremy and his team will continue to enjoy my full support from the back-benches in taking on this uncaring and brutal Tory government - but we need to urgently recognise and re-affirm as a Labour Party that the national security and defence of our country in such a volatile world, is a red line and a matter that should and must transcend party politics, let alone the internal machinations of our own party or personal score-settling.”

A 'sad day'

Caerphilly Labour MP Wayne David said it was a “sad day” for the party when “capable and good people” felt they had to step down from the front bench.

On the BBC, Mr Doughty attacked the briefing against Mr McFadden, saying: “I think that things that are being said, that are being briefed out, that I’ve seen being briefed out this morning are simply not true. Undoubtedly they will do it about other individuals; undoubtedly they will do it about me.

“And unfortunately one of reasons I agreed to serve under Jeremy was actually his comments about ‘new politics’, about being open, about being transparent, about being honest, about being straight-talking. And certainly that seemed to be the case for the first few weeks and months of his leadership and I was perfectly content with that, even on areas where I disagreed with him...

“But unfortunately there is a tendency of some of those around him and in his team to be conducting some pretty unpleasant operations against people who have loyally served the party in government and in opposition.”

Mr Doughty dismissed claims that Mr McFadden was fired for disloyalty as opposed to comments in which he argued the West should not always be blamed for terrorist attacks.

He said: “It’s simply not true. It’s really sad, actually, that the number of lies and unfortunate statements that are coming out of the leader’s office about this situation. I was with Pat just after he was informed and it was very clear what he had been told were the reasons for his sacking.”

'Threat to national security'

Conservative Defence Secretary Michael Fallon said: “This reshuffle shows that a divided Labour Party is a threat to national security. The Labour party has a leader who would abolish the Armed Forces and withdraw from Nato, a shadow chancellor who wanted to disband MI5, and now a shadow defence secretary who would scrap our nuclear deterrent.

“North Korea’s deeply disturbing claim to have exploded its first hydrogen bomb underlines the importance of taking our national security seriously, not handing it to a Labour Party that would unilaterally disarm Britain.”

Welsh Conservative leader Andrew RT Davies said: “While I praise Stephen Doughty for taking a principled stance on this issue, his resignation on live TV shows just how much disarray the Labour Party is in. They cannot even keep their own house in order... Some of their moderate MPs have been sacked and slapped down for expressing sensible views such as condemning the appalling terrorist attacks in Paris...

“The Labour Party chose Jeremy Corbyn as leader by an overwhelming margin, and a number of Assembly Members – including Health Minister Mark Drakeford – publicly backed him. He has a dangerous outlook.

Mr Davies continued: “Jeremy Corbyn’s Labour party have been in power in Wales for the last 17 years, and are a risk to the financial security of the Welsh people.”